Recyclable aerosol can with depressurisation system and tool for depressurising such a can

ABSTRACT

A recyclable aerosol can including a barrel, a dome, a valve support and a base. The base of the can is perforated at the centre thereof with a hole receiving an elastomer insert or plug crimped in the hole. The insert includes an upper part and a lower part joined by a constriction in order to be accommodated in the peripheral wall of the hole in order to form a sealed plug once inserted into the hole.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No. PCT/EP2020/058071, having an International Filing Date of 24 Mar. 2020, which designated the United States of America, and which International Application was published under PCT Article 21(2) as WO Publication No. 2020/193503 A1, which claims priority from and the benefit of French Patent Application No. 1903083, filed on 25 Mar. 2019, the disclosures of which are incorporated herein by reference in their entireties.

BACKGROUND 1. Technical Field

The present disclosure relates to a recyclable aerosol can which is provided for recycling purposes with a depressurization system and a depressurization tool for depressurizing such a housing.

The present disclosure relates to the field of aerosol cans containing products to be sprayed, such as paints or lubricants for example.

2. Description of Related Art

The technology of aerosol cans which can be disposed of after use and contain a product to be sprayed and a propellant gas is widespread.

For technical products packaged in aerosol-generating cans (commonly referred to as aerosols), in particular paints, a professional market is very important.

In such a market, the aerosol cans are collected when they have been used, but when a product has been used up and the can emptied of its contents, it goes to a household hazardous waste (HHW) facility and is usually incinerated instead of being put to profitable use in a conventional metal-recycling facility.

This is because, after full utilization, the can still contains a minimum residual amount of active product, generally less than 5 grams, and a flammable residual gas phase with a residual pressure that is lower than the initial internal pressure (initial internal pressure of about 3 to 4 bar), and this makes it unsuitable for processing as simple metal waste.

However, the can is an item of waste made primarily of metal, if the precaution is taken of removing the diffuser portion, itself made of recyclable PP, in sorting operations.

SUMMARY

In view of this prior art, the present disclosure provides a recyclable aerosol can.

For this purpose, the present disclosure firstly provides a recyclable aerosol can having a barrel, usually referred to as a body, a dome to which there is crimped a valve holder fitted with a valve, and a bottom, wherein the bottom of the can is pierced at its center with a hole which receives an elastomer insert or plug crimped into the hole, the insert having an upper portion and a lower portion that are joined by a constriction for receiving the peripheral wall of the hole so as to form a sealed plug once it has been inserted in the hole.

The diameter of the hole is such that the can retains good resistance to pressure, and in a traditional application the diameter of the hole is less than 5 mm.

The upper portion of the insert advantageously forms a substantially spherical or oval cap having a domed upper face and a flat lower face, and the lower portion of the insert is a frustoconical portion which flares out away from its junction with the flat lower face of the upper portion at the constriction.

The diameter of the insert at the constriction between the lower portion and the upper portion of the insert is slightly greater than the diameter of the hole, so as to produce a sealed junction with the bottom of the can. Typically, the diameter of the insert at the constriction is between 5 and 20% greater than the diameter of the hole, depending on the nature of the elastomer.

A base of the upper portion of the insert has a diameter greater than the diameter of the hole, this diameter being determined to allow both forcible passage of the upper portion through the hole and retention of the upper portion under the pressure of the gas in the can, and also sealing of the insert/bottom connection.

The present disclosure also relates to a system which has a can according to the present disclosure and a depressurization tool comprising a support provided with a bottom having a domed upper face, which has a curvature that matches the external surface of the bottom of the can and is provided with a central punch, which protrudes from a central portion of the bottom and is designed to drive the insert into the can, the central punch having a point provided with a tubular central channel that opens into a vent under the tool to allow a gas to be discharged and expand under the tool.

The tool may possibly be supplemented by a reservoir, disposed under the tool, for collecting product residues.

The base of the central punch is advantageously surrounded by an O-ring seal to prevent product from spraying out around the punch when the insert is driven into the can by the punch.

The tool preferably has a peripheral wall around the bottom of the tool, said wall forming a guide for inserting the bottom of the can into the tool and pushing the insert back into the can.

The present disclosure lastly relates to a method for emptying an aerosol can by means of the system according to the present disclosure, comprising the following sequence of steps:

-   -   moving the bottom of the can closer to the housing of the tool         above the bottom of the tool, with the punch protruding from the         bottom of the tool being directed toward the insert;     -   pressing the bottom of the can into the tool so that the front         point of the punch drives the insert into the can, with the         barrel of the can being held by the peripheral wall of the tool;     -   allowing the residual gas and the residual active product to be         discharged from the pierced aerosol can via the channel formed         in the punch;

in such a way that the pierced can, which has been emptied of its residual contents, can pass to a conventional recycling facility for metal packaging.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, details and advantages of the present disclosure will become apparent on reading the detailed description which describes exemplary embodiments of the present disclosure with reference to the appended drawings, in which:

FIG. 1 shows a sectional side view of a metal can of the prior art;

FIG. 2 shows a sectional side view of a metal can of the prior art which has been fitted with its valve and filled;

FIG. 3A shows a sectional side view of a metal can of the present disclosure before a valve has been mounted;

FIG. 3B shows a complete can of the present disclosure;

FIG. 4A shows a perspective side view of a depressurization tool according to one aspect of the present disclosure;

FIG. 4B shows a sectional side view of the depressurization tool in FIG. 4A;

FIG. 5A; FIG. 5B; FIG. 5C show sectional side views of the steps for emptying a can of the present disclosure.

DETAILED DESCRIPTION

The drawings and the description below relate to exemplary aspects that may make it easier to understand the present disclosure, but also contribute to the definition thereof, as the case may be.

FIGS. 1 and 2 show an aerosol can of the prior art, which has a barrel 10, a concave bottom 20, and a dome 30 which holds a valve 40. The bottom and the barrel are connected by means of a first annular crimp 12, the barrel and the dome are connected by means of a second annular crimp 14, and the dome and a valve-holding cup 42 are connected by a third annular crimp 32.

The crimps are optionally provided with rubber seals which ensure a good connection between the parts and perfect sealing of the can.

The aerosol valve 40 is crimped to the dome of the can once the can has been filled with the active product. The function of the valve, which generally has a dip tube, is to release the product via its opening and to seal the aerosol when it is not actuated.

Such an aerosol can is designed to withstand internal pressures of from 12 to 18 bar.

The can contains a liquid or pasty product 60 to be sprayed through the valve, which is propelled by a pressurized gas 50 and rises toward the valve via a dip tube 46.

Generally, the active product is put in the can before the valve is crimped, and the liquefied gas is introduced via the valve after the valve has been crimped.

The full can contains a liquid mixture of product to be sprayed (for example a paint or a lubricant) and liquefied propellant gas (such as a co-solvent of the product). When the valve is open, the product, propelled by the pressure of the gas, escapes via the collection tube toward the valve and the diffusion outlet.

According to FIGS. 3A and 3B, the present disclosure consists in fitting the bottom of the can with a depressurization device, it being possible to actuate this device at the end of life of the can such that the residual portion of active product and gas is discharged from the can, which then becomes an item of conventional metal-packaging waste which is compatible with a normal recycling facility for metal packaging.

For this purpose, the bottom 20 of the can is pierced at its center with a hole 22, visible in FIG. 5C, which has a diameter less than about 5 mm such that the can retains good resistance to pressure. A specific elastomer insert or plug 70 is crimped into this hole on the production line of the can either at the end of manufacture of the metal portion of the can, before it is filled with the product as shown in FIG. 3A, or for example during the manufacture of the bottom of the can 20 which will be crimped to the body of the can, with the insert in place, by means of crimping wings 21, which are folded over an annular pressing of the can.

The insert 70 has an upper portion 71 which forms a substantially spherical or oval cap having a domed upper face and a flat lower face, and a frustoconical lower portion 72 which flares out away from its junction with the flat lower face of the upper portion so as to form a sealed plug once it has been inserted in the hole 22.

In order to ensure an effective seal, the diameter of the frustoconical lower portion at the junction with the cap will be slightly greater than the diameter of the hole 22 so as to produce a sealed junction with the bottom 20 of the can.

The base of the cap 71 of the insert 70 will have a diameter greater than that of the hole 22, this diameter being determined to allow both forcible passage of the cap through the hole and retention of the cap under the pressure of the gas in the can, and also sealing of the insert/bottom connection.

The can fitted with this specific bottom and provided with the insert should withstand the usual stresses of resisting the internal pressure of 18 to 20 bar and be sealed in a temperature range of from −20° C. to +60° C. at the abovementioned pressure.

The insert 70 with its adapted shape is made with an elastomer that is compatible with the formula of the active product and of the liquefied propellant gas at the abovementioned pressures and temperatures. An insert in particular made of an elastomer of the nitrile or Teflon type, which are elastomers that are not very reactive and have good shape retention over time and with respect to chemical attack, will be preferred.

FIG. 3B shows the can fitted with its insert 70 during use, the product 60 being propelled out of the can by the gas 50 when a diffuser 44 mounted on the valve 40 is pressed A.

FIGS. 4A and 4B show a tool suitable for removing the insert at the end of use of the can, when the latter is empty.

The tool as described is made up of a support 100 in the form of a cup, having a bottom provided with an upper face 110 forming a dome, which matches the external surface of the bottom 20 of the can. According to the present disclosure, the bottom is provided with a central punch 130, which protrudes from the middle of the bottom.

The punch has a point 132 provided with a tubular central channel 131 which opens into a vent 133 under the tool to allow the gas to be discharged and expand under the tool.

The tool may optionally be supplemented by a reservoir, disposed under the tool, for collecting product residues.

At the base of the punch 130, the tool has an O-ring 140 to prevent product from spraying out around the punch when the insert is driven into the can by the punch.

The tool lastly has a peripheral wall 120 which forms a guide for inserting the bottom of the can into the tool and pushing the insert back into the can.

FIGS. 5A to 5C illustrate the steps for removing the insert and emptying the can.

In FIG. 5A, the user who has removed the diffuser 44 moves the bottom 20 of the can closer to the housing of the tool above the bottom 110 of the tool. The punch, which protrudes from the bottom of the tool, is directed toward the insert.

In FIG. 5B, the user presses the bottom of the can into the tool and the barrel of the can is held by the peripheral wall 120 while the front point 132 of the punch is used to drive the insert into the can, this allowing the residual gas and the residual active product to be discharged from the pierced aerosol can via the hole 131 formed in the punch.

The pierced can, which has been emptied of its residual contents, shown in FIG. 5C can thus be considered to be a conventional item of metal packaging and go to a standard recycling facility for metal packaging and no longer be considered to be HHW, since the non-metallic portion of the valve 40, the tube 46 and the insert 70 in the can remain negligible in terms of contaminating the metal of the can in a conventional metal-recycling facility. 

What is claimed is:
 1. A recyclable aerosol can having a barrel, a dome which holds a valve, and a bottom, characterized in that the bottom of the can is pierced at its center with a hole which receives an elastomer plug or insert crimped into the hole, the insert having an upper portion and a lower portion that are joined by a constriction for receiving the peripheral wall of the hole so as to form a sealed plug once it has been inserted in the hole.
 2. The can as claimed in claim 1, wherein the diameter of the hole is such that the can retains good resistance to pressure.
 3. The can as claimed in claim 1, wherein the upper portion of the insert forms a substantially spherical or oval cap having a domed upper face and a flat lower face, and the lower portion of the insert is a frustoconical portion which flares out away from its junction with the flat lower face of the upper portion at the constriction.
 4. The can as claimed in claim 1, wherein the constriction between the lower portion and the upper portion of the insert has a diameter slightly greater than the diameter of the hole, so as to produce a sealed junction with the bottom of the can.
 5. The can as claimed in claim 1, wherein a base of the upper portion of the insert has a diameter greater than the diameter of the hole, this diameter being determined to allow both forcible passage of the upper portion through the hole and retention of the upper portion under the pressure of the gas in the can, and also sealing of the insert/bottom connection.
 6. A depressurization system for a recyclable can, characterized in that it has a can as claimed in claim 1 and a depressurization tool comprising a support provided with a bottom having a domed upper face, which has a curvature that matches the external surface of the bottom of the can and is provided with a central punch, which protrudes from a central portion of the bottom and is designed to drive the insert into the can, the central punch having a point provided with a tubular central channel that opens into a vent under the tool to allow a gas to be discharged and expand under the tool.
 7. The depressurization system as claimed in claim 6, wherein the tool is supplemented by a reservoir, placed under the tool, for collecting product residues.
 8. The depressurization system as claimed in claim 6, wherein the base of the central punch is surrounded by an O-ring to prevent product from spraying out around the punch when the insert is driven into the can by the punch.
 9. The depressurization system as claimed in claim 6, wherein the tool has a peripheral wall around the bottom of the tool, said wall forming a guide for inserting the bottom of the can into the tool and pushing the insert back into the housing.
 10. A method for emptying an aerosol can by means of the system as claimed in claim 6, comprising the following sequence of steps: moving the bottom of the can closer to the housing of the tool above the bottom of the tool, with the punch projecting from the bottom of the tool being directed toward the insert; pressing the bottom of the can into the tool so that the front point of the punch drives the insert into the can, with the barrel of the can being held by the peripheral wall of the tool; allowing the residual gas and the residual active product to be discharged from the pierced aerosol can via the channel formed in the punch; in such a way that the pierced can, which has been emptied of its residual contents, can pass to a recycling facility for metal packaging. 